"Figure 2" of "Real-time antiproton annihilation vertexing with sub-micron resolution"

The distribution in thickness of the tracks in recorded antiprotons events as well as for 4-MeV protons. We attribute the higher-thickness peak of the antiproton distribution to tracks left in the sensor by protons and the lower peak to tracks left by pions. The distribution in thickness of tracks left by 4-MeV protons within the detector matches the topmost part of the distribution in thickness of proton tracks. We attribute the difference between the distributions mainly to the difference in energy spectrum of the protons.